Intestinal Obstruction: Types, Causes, Symptoms, Diagnosis, Management, Complications Nursing Diagnosis


Intestinal obstruction is an interruption in the normal flow of intestinal contents along the intestinal tract. The block may occur in the small or large intestine, may be complete or incomplete, may be mechanical or paralytic, and may or may not compromise the vascular supply. Obstruction most frequently occurs in the young and the old.

Pathophysiology and Etiology of Intestinal Obstruction

Types and Causes of Intestinal Obstruction

1. Mechanical obstruction—a physical block to the passage of intestinal contents without disturbing the blood supply of the bowel. High small-bowel (jejunal) or low small-bowel (ileal) obstruction occurs four times more frequently than colonic obstruction. Causes include: 

a. Extrinsic—adhesions from surgery, hernia, wound dehiscence, masses, volvulus (twisted loop of intestine). Up to 70% of small-bowel obstructions are caused by adhesions. 

b. Intrinsic—hematoma, tumour, intussusception (telescoping of an intestinal wall into itself), stricture or stenosis, congenital (atresia, imperforate anus), trauma, inflammatory diseases (Crohn’s, diverticulitis, ulcerative colitis). 

c. Intraluminal—foreign body, faecal or barium impaction, polyp, gallstones, meconium in infants

d. In postoperative patients, approximately 90% of mechanical obstructions are due to adhesions. In nonsurgical patients, hernia (most often inguinal) is the most common cause of mechanical obstruction.

2. Paralytic (adynamic, neurogenic) ileus. 

a. Peristalsis is ineffective (diminished motor activity perhaps because of toxic or traumatic disturbance of the autonomic nervous system). 

b. There is no physical obstruction and no interrupted blood supply. 

c. Disappears spontaneously after 2 to 3 days. d. Causes include: 

 i. Spinal cord injuries; vertebral fractures.

 ii. Postoperatively after any abdominal surgery. 

 iii. Peritonitis, pneumonia. 

 iv. Wound dehiscence (breakdown). 

 v. GI tract surgery.

3. Strangulation—obstruction compromises blood supply, leading to gangrene of the intestinal wall. Caused by prolonged mechanical obstruction.

Altered Physiology of Intestinal Obstruction

 1. Increased peristalsis, distention by fluid and gas, and increased bacterial growth proximal to the obstruction. The intestine empties distally. 

 2. Increased secretions into the intestine are associated with a diminution in the bowel’s absorptive capacity. 

 3. The accumulation of gases, secretions, and oral intake above the obstruction causes increasing intraluminal pressure.

4. Venous pressure in the affected area increases and circulatory stasis and oedema result. 

5. Bowel necrosis may occur because of anoxia and compression of the terminal branches of the mesenteric artery. 

6. Bacteria and toxins pass across the intestinal membranes into the abdominal cavity, thereby leading to peritonitis. 

7. “Closed-loop” obstruction is a condition in which the intestinal segment is occluded at both ends, preventing either the downward passage or the regurgitation of intestinal contents.

Clinical Manifestations/Symptoms of Intestinal Obstruction

Fever, peritoneal irritation, increased WBC count, toxicity, and shock may develop with all types of intestinal obstruction. 

1. Simple mechanical—high small bowel: colic (cramps), mid to upper abdomen, some distention, early bilious vomiting, increased bowel sounds (high-pitched tinkling heard at brief intervals), minimal diffuse tenderness. 

2. Simple mechanical—low small bowel: significant colic (cramps), midabdominal, considerable distention, vomiting slight or absent, later feculent, increased bowel sounds and “hush” sounds, minimal diffuse tenderness. 

3. Simple mechanical—colon: cramps (mid- to lower abdomen), later-appearing distention, then vomiting may develop (feculent), increase in bowel sounds, minimal diffuse tenderness. 

4. Partial chronic mechanical—may occur with granulomatous bowel in Crohn’s disease. Symptoms are cramping, abdominal pain, mild distention, and diarrhoea. 

5. Strangulation symptoms are initially those of mechanical obstruction, but progress rapidly—pain is severe, continuous, and localized. There is moderate distention, persistent vomiting usually decreased bowel sounds and marked localized tenderness. Stools or vomitus become bloody or contain occult blood.

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Diagnostic Evaluation of Intestinal Obstruction

1. Fecal material aspiration from NG tube. 

2. Abdominal and chest x-rays. 

a. May show the presence and location of small or large intestinal distention, gas or fluid. 

b. “Bird beak” lesion in colonic volvulus. 

c. Foreign body visualization. 

3. Contrast studies. 

a. Barium enema may diagnose colon obstruction or intussusception. 

b. Ileus may be identified by oral barium or Gastrografin. 

4. Laboratory tests. 

a. May show decreased sodium, potassium, and chloride levels due to vomiting. 

b. Elevated WBC counts due to inflammation; marked increase with necrosis, strangulation, or peritonitis. 

c. Serum amylase may be elevated from irritation of the pancreas by the bowel loop. 

5. Flexible sigmoidoscopy or colonoscopy may identify the source of the obstruction such as tumour or stricture.

Management Nonsurgical Management of Intestinal Obstruction

1. Correction of fluid and electrolyte imbalances with normal saline or Ringer’s solution with potassium as required. 

2. NG suction to decompress bowel and decrease risk of perforation. 

3. Treatment of shock and peritonitis. 

4. TPN may be necessary to correct protein deficiency from chronic obstruction, paralytic ileus, or infection. 

5. Analgesics and sedatives, avoiding opiates due to GI motility inhibition. 6. Antibiotics to prevent or treat infection. 

7.  Ambulation for patients with paralytic ileus to encourage return of peristalsis.

Surgery for Intestinal Obstruction

Consists of relieving the obstruction. Options include: 

1. Closed bowel procedures: lysis of adhesions, reduction of volvulus, intussusception, or incarcerated hernia. 

2. Enterotomy for removal of foreign bodies or bezoars. 

3. Resection of bowel for obstructing lesions, or strangulated bowel with end-to-end anastomosis. 

4. Intestinal bypass around the obstruction.

Complications of Intestinal Obstruction

1. Dehydration due to loss of water, sodium, and chloride. 

2. Peritonitis. 

3. Shock due to loss of electrolytes and dehydration. 

4. Death due to shock.

Nursing Assessment of Intestinal Obstruction

 1. Assess the nature and location of the patient’s pain, the presence or absence of distention, flatus, defecation, emesis, and constipation. 

2. Listen for high-pitched bowel sounds, peristaltic rushes, or absence of bowel sounds. 

3. Assess vital signs

Nursing Diagnoses of Intestinal Obstruction

▶ Acute Pain related to obstruction, distention, and strangulation.

▶ Risk for Deficient Fluid Volume related to impaired fluid intake, vomiting, and diarrhoea from intestinal obstruction.

▶ Diarrhoea related to obstruction. 

▶ Ineffective Breathing Pattern related to abdominal distention, interfering with normal lung expansion.

▶ Risk for Injury related to complications and severity of illness.

▶ Fear related to life-threatening symptoms of intestinal obstruction.

Nursing Interventions of Intestinal Obstruction

Achieving Pain Relief 

1. Administer prescribed analgesics. 

2. Provide supportive care during NG intubation to assist with discomfort. 

3. To relieve air-fluid lock syndrome, turn the patient from a supine to a prone position every 10 minutes until enough flatus is passed to decompress the abdomen. A rectal tube may be indicated.

Maintaining Electrolyte and Fluid Balance 

1. Measure and record all intake and output. 

2. Administer IV fluids and parenteral nutrition as prescribed. 

3. Monitor electrolytes, urinalysis, haemoglobin, and blood cell counts, and report any abnormalities. 

4. Monitor urine output to assess renal function and to detect urine retention due to bladder compressions by the distended intestine. 

5. Monitor vital signs; a drop in BP may indicate decreased circulatory volume due to blood loss from a strangulated hernia.

Maintaining Normal Bowel Elimination 

1. Collect stool samples to test for occult blood, if ordered. 

2. Maintain adequate fluid balance. 

3. Record the amount and consistency of stools. 

4. Maintain NG tube as prescribed to decompress bowel.

Maintaining Proper Lung Ventilation 

1. Keep the patient in Fowler’s position to promote ventilation and relieve abdominal distention. 

. Monitor ABG levels for oxygenation levels, if ordered.

Preventing Injury Due to Complications 

1. Prevent infarction by carefully assessing the patient’s status; pain that increases in intensity or becomes localized or continuous may herald strangulation. 

2. Detect early signs of peritonitis, such as rigidity and tenderness, in an effort to minimize this complication. 

3. Avoid enemas, which may distort an x-ray or make a partial obstruction worse. 

4. Observe for signs of shock—pallor, tachycardia, hypotension. 

5. Watch for signs of: 

a. Metabolic alkalosis (slow, shallow respirations; changes in sensorium; tetany). 

b. Metabolic acidosis (disorientation; deep, rapid breathing; weakness; and shortness of breath on exertion).

Relieving Fears 

1. Recognize the patient’s concerns and initiate measures to provide emotional support. 

2. Encourage the presence of a support person.


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